An optimized framework for simultaneous EEG-fMRI at 7T enabling safe, high-quality human brain imaging with...

Area of Science:

• Neuroimaging
• Biophysics
• Medical Engineering

Background:

• Simultaneous electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) offer advanced non-invasive human brain exploration.
• Ultra-high field (7 Tesla) MRI provides superior spatial and temporal resolution but faces challenges with EEG integration due to interference.

Purpose of the Study:

• To develop and validate a novel EEG-fMRI acquisition framework for clinical 7T systems.
• To overcome cross-modal interference and physical constraints hindering 7T EEG-fMRI.

Main Methods:

• Developed a 7T EEG-fMRI framework incorporating compact EEG transmission, reference sensors for artifact correction, and adapted leads for RF coil compatibility.
• Tested two implementations: an in-house adapted cap and a manufacturer prototype.
• Conducted comprehensive human evaluations of simultaneous EEG-fMRI acquisitions.

Main Results:

• Simultaneous sub-millimeter resolution fMRI and EEG acquisitions were safely performed on a clinical 7T system.
• EEG introduced mild perturbations (6-11% temporal SNR loss) to fMRI, without impacting resting-state network or visual response detection.
• Corrected EEG artifacts allowed for spatial, spectral, and temporal characteristics comparable to outside recordings, detecting key neural features.

Conclusions:

• The developed EEG-fMRI framework is a viable and effective tool for advanced neuroimaging at 7T.
• This technique unlocks new possibilities for non-invasive brain research by combining high spatiotemporal resolution.
• The framework's accessibility and performance pave the way for broader adoption in the neuroimaging community.